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path: root/drivers/mmc/host/mmc_spi.c
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Diffstat (limited to 'drivers/mmc/host/mmc_spi.c')
-rw-r--r--drivers/mmc/host/mmc_spi.c27
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 69e1442ff2e2..72f8bde4877a 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -612,6 +612,7 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
struct spi_device *spi = host->spi;
int status, i;
struct scratch *scratch = host->data;
+ u32 pattern;
if (host->mmc->use_spi_crc)
scratch->crc_val = cpu_to_be16(
@@ -639,8 +640,27 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
* doesn't necessarily tell whether the write operation succeeded;
* it just says if the transmission was ok and whether *earlier*
* writes succeeded; see the standard.
+ *
+ * In practice, there are (even modern SDHC-)cards which are late
+ * in sending the response, and miss the time frame by a few bits,
+ * so we have to cope with this situation and check the response
+ * bit-by-bit. Arggh!!!
*/
- switch (SPI_MMC_RESPONSE_CODE(scratch->status[0])) {
+ pattern = scratch->status[0] << 24;
+ pattern |= scratch->status[1] << 16;
+ pattern |= scratch->status[2] << 8;
+ pattern |= scratch->status[3];
+
+ /* First 3 bit of pattern are undefined */
+ pattern |= 0xE0000000;
+
+ /* left-adjust to leading 0 bit */
+ while (pattern & 0x80000000)
+ pattern <<= 1;
+ /* right-adjust for pattern matching. Code is in bit 4..0 now. */
+ pattern >>= 27;
+
+ switch (pattern) {
case SPI_RESPONSE_ACCEPTED:
status = 0;
break;
@@ -671,8 +691,9 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
/* Return when not busy. If we didn't collect that status yet,
* we'll need some more I/O.
*/
- for (i = 1; i < sizeof(scratch->status); i++) {
- if (scratch->status[i] != 0)
+ for (i = 4; i < sizeof(scratch->status); i++) {
+ /* card is non-busy if the most recent bit is 1 */
+ if (scratch->status[i] & 0x01)
return 0;
}
return mmc_spi_wait_unbusy(host, timeout);